JMortensen

I agree, but think you're underestimating the hassle of proper ducts. Do some searching on that and you'll see that you probably won't be able to turn the wheel all the way to lock and you'll lose some ground clearance. If you put ITS ducting on a street car I think it would be ripped off in a couple hundred miles.

The problem is that the stickier the tires, the more heat you can put into the brakes. For tracking a Z with sticky tires I think you need some pretty serious ventilation to allow the stock calipers and rotors to keep up. I've been on the track with slicks and half-assed ventilation and boiled Super Blue brake fluid in less than 5 laps with 4 piston front on solid rotors and 280ZX rear disk. When this happens the pedal goes straight to the floor, no warning, pumping doesn't do much, you're pretty well screwed. Getting a vented rotor in the front seems to be the key to running on the track without a lot of ventilation (vent tubes tend to get torn up on the street so not the most desirable fix). Toyota calipers on stock rotors is better than stock in terms of increasing heat capacity, but not by much, and can really screw up the bias and lead to less effective braking even if it works for another lap or two before it fails. Pads help a lot, but you still need to be able to dissipate the heat, and if you can't get the heat out of the system you're still going to have trouble, although you might put it off for a couple more laps because your pads didn't give up before the fluid boiled.

I've had customers with American cars that have run 3 tubes of oil with no ill effects. I'd drain a bit and then add the second tube. Do some figure 8's to get the additive spread around. I've never heard of damage caused by chatter and I used to work with a guy who intentionally didn't run any modifier at all because he thought it made the LSD weaker. How much is too much... ???

Add friction modifier to reduce chatter or pull your shims out. There are other CLSD options, KAAZ, OS Giken, etc. Very expensive, but better designs than the Nissan unit in that they have more clutches and they have 1.5 and 2 way operation.

Lots of stiction in poly bushings. If you use the spreader I linked to, then you won't have to fight to get the strut in there. Once you get it in when you tighten the spindle pin nuts it draws everything back together. You can sand down the bushings until they aren't so much longer than the sleeves and even add zerk fittings on the outers so that you can grease the bushings, but in the end, poly bushings are going to cause a lot of stiction.

Yes, they are necessary for the strut to change its angle as the suspension compresses and extends. Not necessary to allow for twisting, so you could replace the monoballs with a big rubber bushing and be OK, but you can't replace the monoball with a solid insert. Well, you can, it's just not a good idea and something will break very quickly.

Did what I should have done in the first place and called the local motorcycle shop and asked if they had SA helmets or knew anyone that did. They pointed me to a race shop about 20 miles from here that stocks a bunch of different brands. Sometimes common sense just takes a vacation. For anyone in Seattle: http://www.speedwaremotorsports.com/

Looking for SA2010 and would like to use HANS when I get to the big track and not have to buy another helmet so HANS compatible is what I'm looking for. I picked up a little Miata to do some autoxing with and I need to buy a new helmet to start racing again. In reading various helmet threads on various forums, the advice is always the same: try out a bunch of helmets before you buy. The problem seems to be that nobody stocks SA helmets, so I don't see how you try a bunch of them out other than by ordering a bunch via mail order and then returning the ones that don't fit right. I know that's not my favorite thing when people do it to me, so I'd like to try and figure it out a different way. Anyone have any suggestions as to where one might be able to try on various helmets? Is there a helmet superstore that I'm just not aware of?

LSD's only chatter while turning.

If you're looking for shortnose CV shafts, I think Ross already has that covered. If you wanted to try to use the 88SS VLSD shafts with my short CV shafts and Z31T adapters, I'm betting that would also work, but can't say for sure. I can tell you that I'm not going to make the shortnose CV shafts, unless something changes.

Thanks. Yes, that is a typo.

The splined part of the CV plugs into the diff as Keith suggests. I don't know if the CV shaft itself is longer on the VLSD, I would assume that they're exactly the same as the regular turbo shaft, I'm hoping Keith can answer that once and for all. Wolf Creek uses a 930 Porsche CV joint. It's a very common CV that lots of different cars use because they are strong and cheap. It's like the SBC of CV joints. You're right that it has "plunging" joints on both ends, and when you put power to it it self centers because of the design of the races. I've dealt with Todd several times and think he's a good guy and the product is nicely made from what I've seen in pictures. The center shafts for 930s are easy to come by because just about every dune buggy uses them along with a ton of different race cars, so you can get shafts in any length you want and it's much easier than say, having Z31T shafts machined onesy twosy. If you're comparing the two options, I think it is safe to say that the 930 joints themselves are stronger. They have bigger ball bearings in them. That said, they're bolting to stock companion flanges which are undoubtedly weaker than chromoly parts from M2 or Chequered Flag or MM, and the adapter part is aluminum if I understand correctly. The flange on the stock companion flange is sized for a U-jointed halfshaft and is absolutely tiny and frail looking compared to the CV adapters. The chromoly adapters are at least twice as thick and have a nicely radiused curve towards the much larger flange. If there is going to be a meaningful strength difference, this is where it's at, I think. I think the safety wire suggestion is a good one. I do believe that Keith is right that the M2 / MM / Chequered Flag setup is going to be more bolt on and forget it, and on the other you'll need to constantly be checking bolts (or safety wiring them). Failures of either CV are pretty rare, and I do wonder if the incorrect length of the CV shaft might be a contributing factor in the Z31T shafts. I remember one guy here broke the cage inside the CV shaft. Failures of the CV's is not a common problem, regardless, but that particular failure seems to me like something that might happen when the CV bottoms hard. That's just speculation though. The way you check travel on the Z31 joint is by unbolting the inner CV and moving it all the way in as though you were going to take the CV shaft off. If you move it 1/16", you have very little compression travel available in the joint. If it moves 3/4", you're pretty close to dead center. I don't know anything about the shortnose shaft CV swap. Whatever info I had available at the time was put into my diff post, but I'm sure there are other more detailed suggestions as to how to make that happen. I'm not a huge fan of the shortnose swap because it's a pain to do. You go through all the mounts and all that and you end up with an LSD that just isn't as aggressive. Depending on what it's used for it may be fine, but when I look at it I see minimal weight savings, lots of efforts, and a relatively weak LSD. You still having trouble with those snap rings Keith? This is confusing me: "I think with bolt-on axles without any snap rings to overpower while under the car, your Q45 axles will be a little easier to deal with." If that wasn't a typo and you're actually trying to get that circlip in under the car, then there's your problem. You should assemble the CV shaft on a bench and then put the assembled shaft into the car. No need to mess with all that on your back.

No, definitely not the same 10 tooth pinion. The pitch of the gear will be different because the ring gear has fewer teeth. You really don't want to swap gears even from one 3.90 to another 3.90 if you can avoid it. The ring and pinion can be swapped from one housing to the other, but you need the ring AND the pinion. Much easier to swap the LSD to the 3.90 housing if you still have it.

I don't think so.

The splines have to engage the VLSD part of the diff, so they're longer.

Maybe the two threads could be merged.

Put the carrier in a vise and then use a torque wrench and red loctite.

The RS3's are supposed to be pretty damn good, as are the Star Specs. I just bought R1R's for my Miata, they're supposed to be good in rain but not so good in extreme heat, so that might be a better choice for Seattle than SoCal, although a friend of mine pulled a 2:06 at Buttonwillow CW13 on them in a stock Evo, so they must not be that bad.

4.38's came in the R31 Skylines IIRC. Stony here was importing them from Japan and selling them to ArizonaZCar, but I'm pretty sure that hasn't been going on for a long time now. They do come up for sale occasionally or you might be able to find one overseas and have it imported.

Dammit Dan! Making me want a G-Force transmission now... I'm actually in this same predicament with respect to the gears. I have a 4.11 R200 that I picked up thinking I was going to keep using my NA L6. My tires are 23.5" tall, and with a 6250 redline that puts me at 83 mph in the top of 3rd. So that will probably be my plan for the short term. Longer term that diff doesn't work out so well on a big track, because 5th tops out at 146 and 6th at 216. There are some tracks with LONG straights around here, so I'll be into the ridiculously tall 6th. With a 3.54 2nd goes to 70 (not good) but 5th hits 169 (much better). So my plan is to run the 4.11 for autox, start in 2nd or 3rd and then get a 3.54 for the track. Dan, looks like a 4.11 puts you at 79 in 3rd and 3.90 which is easy to find does 83. I had to fudge the numbers on the calc a bit to come up with your redline speeds by changing the aspect ratio on the tires to 30.

79 280ZX 2+2 manual also. They are rare but they do come up.

I've heard of the Magnum T56, but I don't think they change the gear ratios. You really need separate gears on the counter shaft (or a custom counter shaft) to change the ratios, and I don't think the T56's have that and I'm not aware of anyone who makes such a thing. http://www.keislerauto.com/

Two options: try to find a gear that puts 80 in the top of 2nd as John suggested, or try to find the one where you hit the end of the strip right at redline. I know Cary has been using 2nd gear starts in autox and it would be great if you could drive the whole course in 2nd and not shift at all. Use a trans calculator and plug in your tire size to figure it out. I expect you'll have to experiment at the drag strip to know what your trap speeds are going to be. This calculator has the Camaro T56 ratios: http://webspace.webring.com/people/cz/z_design_studio/

That ball bearing on the pinion is Nissan only, and it's probably the only one that needs replacing. I would pull the pinion and take a look at the others. If you do need them, I can probably get the correct Koyo bearings for you, I would have to check. My suppliers sell Koyo, but it's mostly Toyota truck diff stuff, so the particular ones you need may or may not be common. The problem with checking beforehand is that the pinion bearings changed somewhere along the way. Safest way to go is to pull the pinion and then check the numbers on the bearings directly. I can send you some gear marking compound along with bearings too, or you can get it from Jegs or Summit, etc.

This might help: http://forums.hybridz.org/index.php/topic/105657-300-zx-turbo-cv-shaft-disassembly-and-reassembly/page__p__988589__hl__%2Bcv+%2Bdisassembly__fromsearch__1?do=findComment&comment=988589 How do the balls look? If they aren't pitted you're probably OK. It's tough to tell if that is pitting or just spots on the last pic of the inner race. Does it feel smooth when you articulate the joint?